[Bf-blender-cvs] [9085fb8073e] blender-v2.90-release: Cleanup: expand UserDef pixel-size & DPI documentation

[Campbell Barton]

Commit: 9085fb8073ea645f9f69cc0353334df15921e2e9
Author: Campbell Barton
Date:   Tue Aug 18 11:17:15 2020 +1000
Branches: blender-v2.90-release
https://developer.blender.org/rB9085fb8073ea645f9f69cc0353334df15921e2e9

Cleanup: expand UserDef pixel-size & DPI documentation

Avoid misunderstandings with UI scaling.

===================================================================

M	source/blender/makesdna/DNA_userdef_types.h

===================================================================

diff --git a/source/blender/makesdna/DNA_userdef_types.h b/source/blender/makesdna/DNA_userdef_types.h
index a632d42fd8b..15fe1619ca4 100644
--- a/source/blender/makesdna/DNA_userdef_types.h
+++ b/source/blender/makesdna/DNA_userdef_types.h
@@ -689,16 +689,17 @@ typedef struct UserDef {
   int audioformat;
   int audiochannels;
 
-  /** Setting for UI scale. */
+  /** Setting for UI scale (fractional), before screen DPI has been applied. */
   float ui_scale;
   /** Setting for UI line width. */
   int ui_line_width;
   /** Runtime, full DPI divided by `pixelsize`. */
   int dpi;
-  /** Runtime, multiplier to scale UI elements based on DPI. */
+  /** Runtime, multiplier to scale UI elements based on DPI (fractional). */
   float dpi_fac;
+  /** Runtime, `1.0 / dpi_fac` */
   float inv_dpi_fac;
-  /** Runtime, line width and point size based on DPI. */
+  /** Runtime, calculated from line-width and point-size based on DPI (rounded to int). */
   float pixelsize;
   /** Deprecated, for forward compatibility. */
   int virtual_pixel;